1. Field of the Invention
The present invention generally relates to an electronic device, and more particularly, to an electronic device having a conductive pattern.
2. Description of the Related Art
An inductor or a capacitor is used for phase matching or the like. For example, there is a demand for downsizing, low cost and high performance in a RF (Radio Frequency) system such as mobile phone or a wireless LAN (Local Area Network). An electronic device such as an integrated passive device where passive devices such as an inductor or a capacitor are integrated on a substrate is used in order to satisfy the demand.
It is effective that an integrated passive device is face-down mounted for high performance in a case where the integrated passive device is mounted on a package or a module substrate. A stud bump such as gold, a plated bump or a solder bump is formed on a pad to be connected to outside of the integrated passive device in order to face-down mount the integrated passive device. The stud bump is formed with a wire bonder. The solder bump is formed with a ball mounter. Next, the integrated passive device is mounted on a package or a module substrate with a flip-chip bonder.
Japanese Patent Application Publication No. 2006-157738 discloses an integrated electronic device that uses a spiral-shaped coil on a substrate as an inductor. Japanese Patent Application Publication No. 2007-67236 and U.S. Pat. No. 6,518,165 disclose an inductor where spiral-shaped coils are spaced from each other in a longitudinal direction thereof.
A marker for localization is formed in the integrated passive device in advance, when the bonder such as the wire bonder, the ball mounter or the flip-chip bonder is used. The stud bump or the solder bump is formed or flip-chip mounted with reference to the marker for localization in a case of bonding. The marker for localization is recognized with image recognition in the bonder. Therefore, it is demanded that size or contrast of the marker for localization is determined so that the bonder is image-recognized. It is therefore demanded that the size of the marker for localization is more than a given size and is a conductive pattern having high optical reflectivity. On the other hand, inductive current from the coil is generated in the marker for localization and eddy-current loss is generated and affects inductor property when the marker for localization is enlarged.